This application claims the priority of German patent document 10 2009 033 701.6-16, filed Jul. 16, 2009, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to a method of heating thermoplastic boards, particularly thermoplastic boards having fiber reinforcement, such as carbon fibers.
Conventionally, boards of this type are heated up by means of infrared radiation so that they can be plastically deformed. In the event of unfavorable outside influences, the heating-up of particularly large-surface boards by means of infrared radiation may be inhomogeneous, so that different temperatures are caused on the surface of the thermoplastic board and therefore also in its material at different locations. The heating of the board by means of infrared radiation frequently has the effect that the material of the thermoplastic board will swell, leading to porosities on the surface of the thermoplastic board.
The inventors' experiments concerning the heating of thermoplastic boards by means of heat conduction in a heating system which comes in contact with the surface of the thermoplastic board have shown that there is the risk that the heated material of the thermoplastic board may adhere to the surface of the part of the heating system that comes in contact with the board. The resulting cleaning expenditures for the heating system are quite considerable and the surface of the thermoplastic board will become unsightly as a result of this gluing-together.